✦ Free Finance Tool

Compound Interest Calculator

See how your investments grow over time with compound interest. Calculate future value with monthly contributions and interactive charts.

🏦 Initial Deposit ($)

📆 Monthly Contribution ($)

📅 Years 10

📊 Interest Rate (%)

🔄 Compound Frequency

🎯 Target Goal ($) (optional)

Show inflation-adjusted value

Future Value

Total Contributions

Total Interest Earned

Interest as % of Total

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Needed Monthly for Target

📋 Year-by-Year Breakdown

Year	Starting Balance	Contributions	Interest	Ending Balance

🧮 How Compound Interest Works

Compound interest is the eighth wonder of the world. Your money earns interest, then that interest earns interest too. The longer you let it grow, the more powerful the effect.

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The Power of Compounding

Starting early is the secret to wealth. A 20-year-old saving $500/month at 7% will have over $1 million by age 65. Starting at 40, the same savings yields only $250,000.

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Compound Frequency

Daily compounding earns the most because interest is calculated on your balance every day. Over 30 years, daily vs annual compounding can make a significant difference.

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Setting Goals

Use the target goal feature to find out exactly how much you need to save each month to reach your investment goal within your desired timeframe.

❓ Frequently Asked Questions

How does compound interest work? ▾

Compound interest is interest earned on both your initial principal and the accumulated interest from previous periods. The more frequently interest compounds, the faster your money grows. This is why starting to save early makes such a big difference.

What compounding frequency should I choose? ▾

Daily compounding earns the most interest, followed by monthly, quarterly, semi-annually, and annually. However, the difference between daily and monthly is often small. Choose the option that matches your actual savings account or investment vehicle.

How much should I contribute monthly? ▾

The amount depends on your financial goals and timeline. Even small monthly contributions grow significantly over time due to compound interest. Use the target goal feature to find out what monthly contribution you need to reach your specific savings goal.

What is the Rule of 72? ▾

The Rule of 72 is a quick way to estimate how long it takes for your money to double. Divide 72 by your annual interest rate. For example, at 8% interest, it takes approximately 9 years (72/8 = 9) for your investment to double.